非致命打击武器系统内弹道模拟研究

为了实现对非致命防暴武器发射能量的调节并控制其终点效能,解决"近处不敢打,远处打不到"的问题,提出了恒量动能非致命打击武器系统这一全新理论,在选用了两相流内弹道模型的基础上,采用四阶龙格库塔法,利用MATLAB语言仿真技术进行编程测试,对改进型18.4mm防暴枪的内弹道进行数值仿真,并将模拟结果与实验结果进行分析比对,验证了内弹道模型和仿真结果的正确性,得到了发射过程中,膛内火药燃烧及燃气流动状态的变化规律,弄清了泄气孔位置、气室容积以及泄气孔半径对弹丸初速的影响规律,为非致命防暴武器的进一步发展打下了坚实的基础。     

警棍发射式防暴动能弹的设计与仿真

为了提高警棍发射式防暴动能弹的非致命性终点弹道效能,传统火力实验缺乏科学性计算,不能满足非致命性弹道效能。分析动能弹弹丸的外弹道过程,结合动能弹弹丸的特征量,提出建立和推导出动能弹弹丸的外弹道方程,然后根据外弹道模型,与防暴弹非致命损伤标准进行对比,确定警棍发射式防暴动能弹丸的出口初速与非命性终点弹道效能的关系。利用MATLAB软件进行编程测试,对动能弹外弹道特征进行仿真,结果表明,对一般防暴动能弹丸具有普遍适应性,并为其它枪发式防暴弹和非致使性弹药的研发提供了参考和借鉴。     

基于混合遗传算法的水雷最小安全出管速度

利用气动不平衡式鱼雷发射装置发射水雷武器时,水雷武器经内弹道的高压气做功获得出管速度影响到发射平台的安全性.为了保证水雷武器安全脱离发射平台,必须选择恰当的水雷武器出管速度.中间弹道是内弹道向外弹道的过渡阶段.因此,以气动不平衡式鱼雷发射装置发射水雷武器的中间弹道为研究对象,利用牛顿力学定律建立了中间弹道微分方程形式的运动学模型,并采用混合遗传算法进行仿真,其仿真结果与水雷最小安全出管速度相符合.     

动能橡胶圆球弹优化选择及外弹道仿真

为了为某型动能防暴发射器选择最优橡胶弹丸,建立了橡胶圆球弹外弹道模型,从国内外典型橡胶圆球弹的大小、空气阻力对弹道的影响和终点效应三方面分析了对橡胶圆球弹选择的影响,利用MATLAB仿真软件计算了8 mm、10 mm、15 mm3种直径不同质量条件下的空气阻力对弹道的影响、最大射程、终点速度、飞行时间、动能和比动能;重点分析比动能和K值对弹道特性及终点效应的影响,通过分析和比较,得出了直径为10 mm,质量为2 g的橡胶圆球弹最适合作为某型动能防暴发射器的战斗弹丸;通过分析直径10 mm,质量2 g的橡胶圆球弹不同发射角度情况下的弹道特性和终点效应,结果表明,该橡胶圆球弹存速能力强,发射距离远,安全性高,为某型动能防暴发射器的弹丸制造提供了理论支撑。     

非致命防暴弹外弹道仿真

研究防暴弹外弹道性能优化设计问题,现有的防暴弹外弹道模型缺乏准确性,为提高准确性,提出合理假设和简化处理,改进原有榴弹低速低伸外弹道模型,建立更适合于防暴弹的外弹道模型;利用SIMULINK仿真工具对38mm防暴弹两种设计方案进行外弹道仿真,并将仿真结果与实弹测试进行对比分析,从而选择具有射程远符合设计指标的方案.结果表明:改进优化后的外弹道模型对一般防暴弹具有普遍适应性,为防暴弹设计阶段不同方案的选择提供参考.     

火箭防暴弹发动机的内弹道解析

研究防暴弹发动机燃烧室优化控制问题,为了实现对火箭防暴弹发动机燃烧室内压强的控制并确定其影响因素,解决燃烧室内各点压强分布不均衡的问题,提出了阶段分析法,并引用“零维”压强这一概念,在选用“零维”内弹道模型的基础上,采用龙格库塔法,利用MATLAB语言仿真技术进行编程测试,对“零维”条件下的内弹道进行数值仿真,并将模拟结果与实验结果进行分析比对,验证了内弹道模型和仿真结果的正确性,得出了在发动机工作过程中,燃烧室内压强随时间的变化规律,明确了影响压强的各个因素,为固体火箭发动机内弹道性能研究以及外弹道的计算提供了理论依据.     

基于执勤专用枪的防暴动能弹内弹道仿真研究

针对部队在执勤中枪支管理难的问题,结合无管发射式防暴动能弹的特点,提出了执勤专用枪这一全新概念;在内弹道过程分析及数值计算的基础上,利用MATLAB语言仿真技术进行编程测试,对其内弹道模型进行数值模拟仿真,根据仿真曲线分析了该弹弹丸内弹道运动规律、各项指标之间的相互关系及影响各项指标的因素,仿真结果表明,弹筒内最大压力、弹丸出口速度、管口压力、火药燃烧相对结束位置等指标均符合设计要求,保证了弹体设计符合理论设计要求。     

喷管前置式减后坐武器内弹道机理分析

为了更好的了解拉瓦尔喷管气流反推减后坐结构的工作原理,对它的内弹道过程和喷管内气流运动过程分别建立了欧拉型无牯的一维两相流数学模型.并以5.8mm 1:3径实验枪为对象进行了数值仿真计算,将结果与普通导气式自动步枪内弹道仿真数据进行了对比,得出了喷管前置式减后坐武器发射过程中各种特征参量的变化规律,以及影响减后坐效率的关键参数.计算结果表明:喷管前置式减后坐结构在弹丸出膛口时速度减小5.5%,后坐力减小20.36%.     

基于Adams的某机枪射击密集度仿真

为研究武器结构对射击密集度的影响,提出一种低伸弹道武器射击密集度的分析方法.采用刚柔耦合分析方法和Adams软件建立某机枪的动力学仿真模型,计算两种枪管设计方案的射击密集度.仿真结果为设计人员进行结构设计及优化提供参考依据.     

航天发射可视化仿真接口模块设计

可视化仿真在航天发射弹道设计和分析中起着重要作用.卫星工具包软件STK,是航天领域通用的仿真软件,可以用来实现航天发射数据的可视化.航天任务的方案选择阶段,需要计算多条弹道,在STK界面内进行一系列设置来实现每条弹道的可视化,是非常繁琐的.因此,有必要将可视化的工作模块化.针对航天发射任务的弹道仿真,利用VC 和STK/CONNECT模块,开发了可视化接口模块,该模块能够与弹道数据模块和资源库模块进行交互,获取相关数据,对数据进行转换和处理后,连接STK建立可视化场景.系统设计人员只需在接口模块界面内进行简单操作,便可实现可视化.     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.